A review of the phenomenon of lead white darkening and its conversion treatment

This paper reviews treatment practices, historical and contemporary, for the conversion of darkened lead white, as informed by accounts in artists' treatises, early paint chemistry manuals and the conservation literature. The evolution of treatment methodology is examined with respect to changing views, conservation ethics, and the impact of various treatment methods on paper artifacts. A discussion of related scientific findings illustrates the recent advances in the understanding of factors contributing to the deterioration of lead white pigment and supports the critical evaluation of conversion treatment methods.